为实现不同冲击载荷下的吸能管结构逆向设计,应用复合材料强度和刚度理论,计算得到树脂基纤维增强复合材料正交各向异性的力学参数,同时应用非线性显式有限元算法模拟了轴向冲击载荷作用下管件的动态断裂过程。根据正交设计原理,得到了管件比吸能与其几何参数之间的非线性映射关系,并构造出了相应的响应表面。按照汽车正面碰撞对冲击加速度的要求,应用序列二次规划算法对吸能管进行了优化设计,得到了具有较优吸能效率和较小冲击力峰值的吸能管结构参数。结果显示:方管的变形模式、吸能量、冲击载荷-位移曲线变化趋势、冲击载荷峰值等与试验结果吻合很好;当管件的壁厚、截面长度、管长分别选取2.1、44、200 mm时,可得到设计域内的最大比吸能29.23 J/g。
In order to design energy-absorption tubes for different impact loadings,the dynamic fracture process of composite tubes under axial crash loads was simulated by nonlinear explicit finite element method.The orthotropic material constants for fiber-reinforced polymer were obtained based on the strength and stiffness theory of composites.According to the principle of orthogonal design,the nonlinear mapping relations between specific energy absorption of tubes and their geometry parameters were established,and corresponding response surfaces were constructed.With the restriction of peak acceleration in frontal vehicle collision,the structural parameters of tubes with high specific energy absorption and low peak impact force were optimized by using sequential quadratic programming algorithm.The simulation results show that the deformation modes,absorbed energy,impact force versus displacement curve as well as the peak impact load agree well with that of experiments.The obtained maximum special energy absorption is 29.231J/g when the wall thickness,edge length and tube length of square tube are 2.1,44 and 200mm,respectively.